Nicotine is a component of various tobacco products. Over the years, however, various methods and systems have been developed for providing nicotine to adult subjects without the presence of tobacco plant tissue. Some ways tobacco-free nicotine is provided include transdermal patches, lozenges, and nicotine chewing gums.
Nicotine, or 3-(1-methyl-2-pyrrolidinyl) pyridine, is a tertiary amine with the following structure:

Under ambient conditions, nicotine is an oily, volatile, hygroscopic liquid that is sensitive to light and air. Nicotine's chemical and physical properties present a number of processing and stability issues. For example, because nicotine is volatile, it may evaporate during its incorporation into an oral product such as a gum or lozenge. In an effort to reduce potential processing and stability issues associated with the nicotine compound, a number of nicotine complexes have been developed. For example, one method includes the preparation of a complex of nicotine and an ion exchange resin. A well-known complex that is currently used in the commercially-available nicotine chewing gums is nicotine polacrilex, which is a complex of nicotine and the cation exchange resin AMBERLITE 164.